need comments/suggestions on current project

[Carolina Cricket]

I posted the following message to the photo forum and am reposting here so that kiln casters may assist me:

Altho I have worked in stained glass (cold) since 1990, my fusing experience has been limited. I was intrigued by the BE technical bulletin about using the thick kiln fiber paper for making a casting mold. Here are 3 photos of my first attempt with such a mold. It has NOT been fired yet so I am hoping that you glassers with more experience will comment. I used a double rolled BE amber glass for background. Then a thin purplish/blue (alto it appears brown in the photos) for the butterfly wings and body. It is see through when held up to light and has an irid coating. I then used rods and stringers and bits of glass to finish the design. I didn't have access to clear frit to fill in the spaces between the wings and the body so I used clear amber stringer. Comments? Suggestions?

Photos are at:
http://f1.pg.photos.yahoo.com/ph/cricke ... g+projects

Cricket in Carolina

[charlie holden]

It looks like it should work well to me. I wouldn't take it to full casting temperature, though, or it may thin out too much where the mold is thickest. It would also be interesting as a negative relief in a thick piece of glass. You'ld have to build up mold walls for that. See the BE bulletines on working thick and negative relief casting.

[Carolina Cricket]

Charlie, can you tell me more about casting temperatures? Such as for the full casting you mention, how high? And what temperature (realizing kilns differ) are you recommending?
Cricket in NC

[Tom White]

Cricket, has any of your glass been fired yet? The square edges seem to suggest it has not been fired yet. Do you plan to tack fuse the design to the base glass before slumping it ovet your fiberpaper mold? In your photo of your mold it looks like some places have 3 layers of 1/8" fiberpaper. I would think that BE slump schedule for 1/4" glass thickness would be a good starting point for forming this piece with careful observation to stop the heating when you have the desired result.

Best wishes,
Tom in Texas

[charlie holden]

Charlie, can you tell me more about casting temperatures? Such as for the full casting you mention, how high? And what temperature (realizing kilns differ) are you recommending?
Cricket in NC

Full casting is really a combination of temperature and time. It could be 1425 F for a long time or 1550 for a shorter time. I can't tell you much other than I would stay in the low 1400's and leave some edges on the glass that makes up the design elements. I like texture in the top surface of the glass as well as behind.

I also think this would be a very nice negative relief with a flat surface on top. The problem there might be that the colors would run all over the place before the firing was complete. I think you should try one of these with only one color over the entire surface, cast into a thick tile.

When in doubt fall back on the old habits of testing and observing. Don't risk a big expensive piece until you've worked out the firing details on some small tiles with similar layups. And be sure to look inside your kiln when the glass is hot and take notes on what's happening at set temps and times.

ch